Most good sounding vintage synth oscillators have waveforms that are far from the mathematical "ideal" that they are named after. This gives them extra harmonic

Most good sounding vintage synth oscillators have waveforms that are far from the mathematical "ideal" that they are named after. This gives them extra harmonics and therefore character that vanilla DSP creations generally lack. Same goes for filters, too. When they are meticulously modelled on these originals, then they can sound very good, but otherwise tend to lack the character of the sounds many of us have grown up with.